#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/wait.h>

void writer(int wfd)
{
    const char* str = "hello father, i am child";
    char buffer[128];
    int cnt = 0;
    pid_t pid = getpid();
    while(1)
    {
        snprintf(buffer,sizeof(buffer),"meaasge: %s,pid_t: %d,count: %d\n",str,pid,cnt);
        write(wfd,buffer,strlen(buffer));
        cnt++;
        sleep(1);
    }

}

void reader(int rfd)
{
    char buffer[1024];
    while(1)
    {
        ssize_t n = read(rfd,buffer,sizeof(buffer)-1);
        (void)n;
        printf("father get a message: %s",buffer);
    }
}


int main()
{
    //1.创建管道
    int pipefd[2] ;
    int n = pipe(pipefd);
    if(n<0) return 1;//创建管道失败

    printf("pipefd[0] :%d, pipefd[1] :%d\n",pipefd[0],pipefd[1]);
    pid_t id = fork();

    if(id == 0)
    {
        //child 写
        close(pipefd[0]); //读端关闭

        writer(pipefd[1]);

        exit(0);
    }

    // father 读
    close(pipefd[1]);

    reader(pipefd[0]);
    wait(NULL);

    return 0;
}